What is PDF Bookmark Editor?

Add, edit, reorder, and remove bookmarks (also called outlines or table of contents entries) in PDF files. Add bookmarks to long documents so readers can jump straight to any chapter or section.

Bookmarks are stored as outline entries in the PDF's catalog and link to a destination — usually a page number and a zoom level. This editor parses the outline tree, lets you nest entries up to several levels deep using indent buttons or drag-and-drop, filter long lists by title, preview any target page right beside the list, and writes the updated structure back without re-encoding the page content.

How to use

1. Upload a PDF file. Any existing bookmarks will be displayed in an editable tree view.
2. Add new bookmarks with the Add Bookmark form. Click a bookmark title to jump the preview to that page. Drag any row by its handle to reorder or drop it onto another bookmark to nest it under. Use the indent buttons or move-up and move-down arrows when you want precise single-step changes, and the filter input above the list to find a specific entry in long outlines.
3. Click Save to generate the updated PDF with your bookmark structure, then download it.

When to use

• Adding chapter and section markers to a long thesis, manual, or whitepaper before sharing.
• Cleaning up bookmark titles that scanners or OCR tools generated automatically.
• Re-nesting a flat list of bookmarks into a proper hierarchy after merging multiple PDFs.

Result

A researcher uploads a 150-page thesis PDF and adds chapter bookmarks (Introduction p.1, Methods p.30, Results p.75, Discussion p.120) for easier navigation during review.

FAQ

Will the original PDF be re-rendered or change quality?

No. Only the outline (bookmark) data is rewritten. Page content, fonts, embedded images, and form fields stay byte-identical. File size grows by a few hundred bytes per bookmark for the title strings.

Can a bookmark point to a specific position on the page, not just the page itself?

This tool sets a Fit destination (top of the page at the current zoom). For pixel-precise positions you'd need to write an XYZ destination by hand, which is rare in practice and only honored by a few viewers.

How many bookmarks can I add before the PDF reader gets sluggish?

Adobe Reader and most browsers handle several thousand entries without trouble. Past 10,000 you may see the sidebar take a second to expand. Nest deep hierarchies instead of dumping everything at one level if your TOC is huge.

Why are some existing bookmarks missing after I upload?

Older PDFs sometimes use named destinations rather than direct page references. If the named destination dictionary is missing or broken, the bookmark loses its target. The entry still appears but jumps to page 1 when clicked.

Do bookmarks survive when the PDF is converted to other formats?

When exporting to EPUB or HTML, most converters map bookmarks to chapter headings. Printed PDFs lose them entirely since paper has no clickable navigation. PDF/A preserves the outline but flattens any interactive features.

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